LOS ANGELES — Saturday marked the 50th anniversary of the discovery of the quasar — an extremely bright object powered by matter falling into a super-massive black hole lying in the heart of a galaxy.

First found in 1963, these strange sources of radio waves initially stumped astronomers: They shone as sharply and intensely as nearby stars, but they appeared to be moving away from Earth far too fast to be in our own Milky Way. Scientists called them quasi-stellar radio sources — or quasars for short.

Eventually, astronomers realized that only a black hole had enough power to produce such bright light from such mind-boggling distances. These cosmic beacons offered a glimpse into the very early universe.

California Institute of Technology astronomer Maarten Schmidt discovered the first known quasar, 3C273, on March 16, 1963. He spoke with the Los Angeles Times about his groundbreaking discovery.

Question: How did you come across that first quasar, 3C273?

Answer: The radio astronomers after World War II were producing catalogs of radio sources that were quite reliable. Usually these radio sources were identified with galaxies. 3C273 was one of the first ones where the identification was not with a galaxy. We believed it originally to be a star.

Q: So you measured the object’s redshift, which tells you how much the light from an object is getting stretched out as the object travels away from you. What did this show?

A: Redshifts are just a measure of distance in the universe. High redshifts mean large distances.

If the object were a star, it would have to be in our own galaxy, of course. And the stars in our galaxy have a velocity never larger than 600 kilometers per second — that would be a redshift of 0.2 percent. If a star has a velocity larger than that, it would escape the galaxy. Anything that has a redshift of even 1 percent has to be outside the galaxy.

But when I took a spectrum in 1962 and also in 1963, it turned out that it was redshifted by 16 percent. That corresponds to a velocity off 47,000 kilometers per second.

Q: Did you realize it was in the center of another galaxy?

A: No. These quasars occur in the center of galaxies, but are so incredibly bright that they masked the whole galaxy. That took a long time to establish.

Q: Were you surprised by your own conclusions?

A: Absolutely. My wife still tells me I was pacing the floor in the evening and couldn’t stop.

More in News

A wedding and special events’ planning business has agreed to pay a $200,000 settlement to five employees living in the country illegally after allegedly failing to pay them minimum wages and overtime and discriminating against them because of their race.

The CIA has concluded in a secret assessment that Russia intervened in the 2016 election to help Donald Trump win the presidency, rather than just to undermine confidence in the U.S. electoral system, according to officials briefed on the matter.